| laser capture microdissection of uredinia formed by melampsora larici-populina revealed a transcriptional switch between biotrophy and sporulation. | the foliar rust caused by the basidiomycete melampsora larici-populina is the main disease affecting poplar plantations in europe. the biotrophic status of rust fungi is a major limitation to study gene expression of cell or tissue types during host infection. at the uredinial stage, infected poplar leaves contain distinct rust tissues such as haustoria, infection hyphae, and uredinia with sporogenous hyphae and newly formed asexual urediniospores. laser capture microdissection (lcm) was used to ... | 2010 | 20831407 |
| changes in antioxidant enzyme activities and isozyme profiles in leaves of male and female populus cathayana infected with melampsora larici-populina. | populus cathayana rehd., a dioecious tree species, is widely distributed in the northern, central and southwestern regions of china. in poplars, melampsora larici-populina kleb. is mainly responsible for rust disease, which is considered to be the world's most important disease of poplars. yet, little is known about sex-related responses to rust disease in poplars. the purpose of this work was to determine whether sexually different responses occur in the antioxidant system of poplars after infe ... | 2010 | 19917640 |
| transcriptome profiling in hybrid poplar following interactions with melampsora rust fungi. | in natural conditions, plants are subjected to a combination of biotic stresses and often have to cope with simultaneous pathogen infections. in this report, we aim to understand the global transcriptional response of hybrid poplar nm6 (populus nigra x p. maximowiczii) to infection by two biotrophic melampsora fungi, melampsora larici-populina and m. medusae f. sp. deltoidae. these pathogens triggered different responses after inoculation of poplar leaves. transcript profiling using the genechip ... | 2009 | 19132871 |
| a single gene cluster controls incompatibility and partial resistance to various melampsora larici-populina races in hybrid poplars. | abstract complete cosegregation for race-specific incompatibility with three melampsora larici-populina rust races was observed in five f(1) hybrid progenies of populus, with different patterns among the various progenies. a single gene cluster could explain these segregations: one locus with multiple alleles or two tightly linked loci controlling complete resistance to e1 and e3, and two tightly linked loci for e2. the random amplified polymorphic dna marker opm03/04_480 was linked to that clus ... | 1998 | 18944985 |
| histological aspects of a hypersensitive response in poplar to melampsora larici-populina. | abstract the course of the infection and development of the biotrophic fungus melampsora larici-populina on leaf tissue from the hybrid poplar populus deltoides x p. nigra 'ogy' was monitored at the histological level. leaf disks were inoculated with one of two rust physiological races (e1 and e2), resulting in interactions that were either incompatible (race e1) or compatible (race e2). in the compatible interaction, the fungus rapidly colonized the leaf without inducing any apparent host respo ... | 1999 | 18944764 |
| partial resistance to melampsora larici-populina leaf rust in hybrid poplars: genetic variability in inoculated excised leaf disk bioassay and relationship with complete resistance. | abstract inoculated excised leaf disk technique allows decomposition of poplar partial resistance to melampsora larici-populina leaf rust into key epidemiological components such as latent period (lp), uredinia number (un), uredinia size (us), and spore production (sp) for a given m. larici-populina strain under controlled environmental conditions. three hundred thirty-six genotypes from an interspecific populus deltoides x p. trichocarpa f(1) progeny segregating for complete resistance to m. la ... | 2003 | 18944356 |
| comparison of genetic and virulence diversity of melampsora larici-populina populations on wild and cultivated poplar and influence of the alternate host. | abstract the aims of this study were, first, to compare the genetic and virulence diversity between populations of the rust fungus melampsora larici-populina on wild and cultivated poplar stands and, second, to investigate the influence of the presence of the alternate host of the pathogen, larch, on which its sexual reproduction occurs, on these diversities. nine french m. larici-populina populations collected from poplar trees in autumn and four populations collected from larch trees during th ... | 2006 | 18944059 |
| characterization of two major genetic factors controlling quantitative resistance to melampsora larici-populina leaf rust in hybrid poplars: strain specificity, field expression, combined effects, and relationship with a defeated qualitative resistance gene. | abstract two genetic factors explain a significant proportion of the variability for quantitative resistance to melampsora larici-populina leaf rust in a populus deltoides x p. trichocarpa f(1) progeny. one is inherited from p. deltoides and is associated with a defeated qualitative resistance gene r(1), and the other, r(us), is inherited from p. trichocarpa. to assess the potential contribution of these two factors for durable resistance breeding, 284 genotypes from this f(1) progeny were studi ... | 2004 | 18943707 |
| fine mapping and identification of nucleotide binding site/leucine-rich repeat sequences at the mer locus in populus deltoides 's9-2'. | abstract melampsora larici-populina is the most damaging leaf pathogen for poplar in europe. previous genetic analyses have revealed both qualitative and quantitative resistance to this fungus. as a starting point for positional cloning of the gene or genes conferring qualitative resistance to m. larici-populina races e1, e2, and e3, a local genetic map of the melampsora resistance (mer) locus was constructed based on amplified fragment length polymorphism (aflp) markers. eleven aflp markers wer ... | 2001 | 18943442 |
| genetic structure of the poplar rust fungus melampsora larici-populina: evidence for isolation by distance in europe and recent founder effects overseas. | dispersal has a great impact on the genetic structure of populations, but remains difficult to estimate by direct measures. in particular, gradual and stochastic dispersal are often difficult to assess and to distinguish, although they have different evolutionary consequences. plant pathogens, especially rust fungi, are suspected to display both dispersal modes, though on different spatial scales. in this study, we inferred dispersal capacities of the poplar rust fungus melampsora larici-populin ... | 2008 | 18499532 |
| transcript profiling of poplar leaves upon infection with compatible and incompatible strains of the foliar rust melampsora larici-populina. | to understand key processes governing defense mechanisms in poplar (populus spp.) upon infection with the rust fungus melampsora larici-populina, we used combined histological and molecular techniques to describe the infection of populus trichocarpa x populus deltoides 'beaupré' leaves by compatible and incompatible fungal strains. striking differences in host-tissue infection were observed after 48-h postinoculation (hpi) between compatible and incompatible interactions. no reactive oxygen spec ... | 2007 | 17400708 |
| [genetic diversity of melampsora larici-populina]. | by using its - nrdna-relp, its sequencing, and rapd molecular marker, this paper studied the genetic diversity of 11 isolates in 5 races of melampsora larici-populina from different regions. the results indicated that the genetic differentiation of m. larici-populina was correlated to its geographical distribution, which could be grouped into northern and western geographic populations, and the latter could be grouped into high-mountain forest ecologic type (hmf) and western plain ecologic type ... | 2006 | 17269335 |
| genetic architecture of qualitative and quantitative melampsora larici-populina leaf rust resistance in hybrid poplar: genetic mapping and qtl detection. | in order to elucidate the genetic control of resistance to melampsora larici-populina leaf rust in hybrid poplars, a populus deltoides x p. trichocarpa f(1) progeny was analysed for qualitative and quantitative rust resistances. this progeny was evaluated for three components of quantitative resistance (latent period, uredinia number and uredinia size) to seven m. larici-populina strains in controlled conditions, and for one component of field susceptibility (rust colonization on the most infect ... | 2005 | 15948835 |
| annotation of a 95-kb populus deltoides genomic sequence reveals a disease resistance gene cluster and novel class i and class ii transposable elements. | poplar has become a model system for functional genomics in woody plants. here, we report the sequencing and annotation of the first large contiguous stretch of genomic sequence (95 kb) of poplar, corresponding to a bacterial artificial chromosome clone mapped 0.6 centimorgan from the melampsora larici-populina resistance locus. the annotation revealed 15 putative genetic objects, of which five were classified as hypothetical genes that were similar only with expressed sequence tags from poplar. ... | 2004 | 15085260 |
| genetic analysis of phenotypic variation for ectomycorrhiza formation in an interspecific f1 poplar full-sib family. | a plant's capability to develop ectomycorrhizal symbiosis is under the control of both genetic and environmental factors. in order to determine the roles played by these different factors, we have performed a quantitative genetic analysis of the ability of poplar trees to form ectomycorrhizas. quantitative genetics were applied to an interspecific family of poplar for which the two parental genetic maps had already been described, and for which data analyses concerning fungal aggressors were obt ... | 2005 | 15015061 |
| poplar peroxiredoxin q. a thioredoxin-linked chloroplast antioxidant functional in pathogen defense. | peroxiredoxins are ubiquitous thioredoxin- or glutaredoxin-dependent peroxidases, the function of which is to destroy peroxides. peroxiredoxin q, one of the four plant subtypes, is a homolog of the bacterial bacterioferritin comigratory proteins. we show here that the poplar (populus tremula x populus tremuloides) protein acts as a monomer with an intramolecular disulfide bridge between two conserved cysteines. a wide range of electron donors and substrates was tested. unlike type ii peroxiredox ... | 2004 | 14976238 |
| genetic variation of the riparian pioneer tree species populus nigra. ii. variation in susceptibility to the foliar rust melampsora larici-populina | partial resistance of populus nigra l. to three races of the foliar rust melampsora larici-populina kleb. was studied in a field trial and in laboratory tests, using a collection of p. nigra originating from different places throughout france. no total resistance was found. the partial resistance was split into epidemiological components, which proved to be under genetic control. various patterns of association of epidemiological components values were found. principal components analysis reveal ... | 1999 | 10336707 |
| molecular genetics of rust resistance in poplars (melampsora larici-populina kleb/populus sp.) by bulked segregant analysis in a 2 x 2 factorial mating design. | with random amplified polymorphic dna (rapd) markers, we have tagged a genomic region in populus sp. involved in qualitative resistance to melampsora larici-populina. our approach was based on three steps: use of rapd markers that can be quickly and efficiently researched: application of "bulked segregant analysis" technique on individuals of one interspecific family p. trichocarpa x p. deltoides to search for rapd markers linked to resistance; and validation of these markers in two other famili ... | 1996 | 8722801 |
| the poplar-poplar rust interaction: insights from genomics and transcriptomics. | poplars are extensively cultivated worldwide, and their susceptibility to the leaf rust fungus melampsora larici-populina leads to considerable damages in plantations. despite a good knowledge of the poplar rust life cycle, and particularly the epidemics on poplar, the perennial status of the plant host and the obligate biotrophic lifestyle of the rust fungus are bottlenecks for molecular investigations. following the completion of both m. larici-populina and populus trichocarpa genome sequences ... | 2011 | 22567338 |
| patterns of repeat-induced point mutation in transposable elements of basidiomycete fungi. | transposable elements (tes) are ubiquitous genomic parasites that have prompted the evolution of genome defense systems that restrict their activity. repeat-induced point mutation (rip) is a homology-dependent genome defense that introduces c-to-t transition mutations in duplicated dna sequences and is thought to control the proliferation of selfish repetitive dna. here, we determine the taxonomic distribution of hypermutation patterns indicative of rip among basidiomycetes. we quantify c-to-t t ... | 2012 | 22250128 |
| a comprehensive analysis of genes encoding small secreted proteins identifies candidate effectors in melampsora larici-populina (poplar leaf rust). | the obligate biotrophic rust fungus melampsora larici-populina is the most devastating and widespread pathogen of poplars. studies over recent years have identified various small secreted proteins (ssps) from plant biotrophic filamentous pathogens and have highlighted their role as effectors in host-pathogen interactions. the recent analysis of the m. larici-populina genome sequence has revealed the presence of 1,184 ssp-encoding genes in this rust fungus. in the present study, the expression a ... | 2011 | 22046958 |
| melampsora larici-populina transcript profiling during germination and timecourse infection of poplar leaves reveals dynamic expression patterns associated with virulence and biotrophy. | melampsora larici-populina is responsible for poplar leaf rust disease and causes severe epidemics in poplar plantations in europe. the poplar rust genome has been recently sequenced and, in order to find the genetic determinants associated with its biotrophic lifestyle, we generated a whole-genome custom oligoarray and analyzed transcript profiles of m. larici-populina during the infection timecourse in poplar leaves. different stages were investigated during the asexual development of the rust ... | 2011 | 21644839 |
| the genetic structure of the plant pathogenic fungus melampsora larici-populina on its wild host is extensively impacted by host domestication. | wild and cultivated plants represent very different habitats for pathogens, especially when cultivated plants bear qualitative resistance genes. here, we investigated to what extent the population genetic structure of a plant pathogenic fungus collected on its wild host can be impacted by the deployment of resistant cultivars. we studied one of the main poplar diseases, poplar rust, caused by the fungus melampsora larici-populina. a thousand and fifty individuals sampled from several locations i ... | 2011 | 21627704 |
| from the cover: obligate biotrophy features unraveled by the genomic analysis of rust fungi. | rust fungi are some of the most devastating pathogens of crop plants. they are obligate biotrophs, which extract nutrients only from living plant tissues and cannot grow apart from their hosts. their lifestyle has slowed the dissection of molecular mechanisms underlying host invasion and avoidance or suppression of plant innate immunity. we sequenced the 101-mb genome of melampsora larici-populina, the causal agent of poplar leaf rust, and the 89-mb genome of puccinia graminis f. sp. tritici, th ... | 2011 | 21536894 |